Safety attachment for platform-rockers



(No Model.)

4 R. H. KRALL.

SAFETY ATTAGHMENT FOR PLATFORM ROCKERS. No. 442,485. Patented Dec. 9, 1890.

WITNESSES.

INVENTOI? W4 8* m g A TTOHNE Y S UNITED STATES PATENT OFFICE.

RICHARD ll. KRALL, ()F ALLEfTO\VN, PENNSYLVANIA.

SAFETY ATTACHMENT FOR PLATFORM-ROCKERS.

SPECIFICATION forming part of Letters Patent No. 412,485, dated December 9, 1890.

Application filed April 22, 1890- Serial No. 349,046. (No model.)

To all whom it may concern.-

Be it known that I, RICHARD H. KRALL, of Allentown, in the county of Lehigh and State of Pennsylvania, have invented a new and useful Safety Attachment for Platform-Rock ers, of which the followingis a full, clear, and exact description.

My invention consists in an improved safety attachment for platform-rockers, and has for its objectto provide a means whereby the body of the chair may be conveniently and expeditiously locked to the platform and the said body he held rigidly in an ,upright or in an inclined position.

A further object of the invention is to provide a locking device of simple, durable, and economic construction capable of attachment to any rocker, and which will act as a safetyeheok, preventing the body of the rocker from falling backward should an accident happen to the spring.

The invention consists in the novel construction and combination of the several parts, as will be hereinafter fully set forth, and pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar figures of reference indicate corresponding parts in all the views.

Figure 1 is an elevation of the inner side of a portion of the platform and seat-frame of the chair. Fig. 2 is a plan view-of the same, illustrating the attachment in the position to admit of the body of the chair rocking upon its platform. Fig. 2) is a similar View, illustrating the position of the attachment when the body is locked to the platform. Figs. 4 and 5 are side elevations of one of the links, illustrating diiferent forms of the attached looking devices. Figs. 6 and '7 are face views of the plates adapted to receive the said looking devices. Figs. 6 and 7 also illustrate longitudinal sections through the plates. Fig. 8 is a section through the platform, illustrating the adjusting-screwin side elevation and the said screw as constructed to be i'nanipulated bya wrench or key.

The platform 10, and likewise the body or seat frame 11, of the chair may be of any suitable or approved construction. The body 11 of the chair is connected with the platform by the usual spring12.

Upon the inner face of one side bar of the platform 10 a plate 13, made in two sections, is attached, which plate is provided with a central polygonal recess 1%, as shown in Fig. 6, or with a recess shaped to the contour of a spur-wheel, as illustrated at 15 in Fig. 7. In the center of the recess of the plate an opening 10 is produced, much smaller than the recess 14, which is smaller than and registers with an aperture made in the platform, and through the aperture in the platform and the aperture in the plate the threaded end of a screw 17 is passed from the outer side of the platform, the outer end of which screw may be squared to receive any form of a wrench or key, as shown in Fig. 8, or it may be formed .to the shape of a knob or button 18, as illustrated in Figs. 2 and 3, the latter form being preferred. The screw 17 is also provided with a peripheral groove, into which the walls of the plate-opening 16 are adapted to fit. Thus the screw may be turned without moving laterally.

In connection with the plate 13 two links 19 and 20 are employed, which links are pivotally attached at one end. The link 19 is socured in any suitable or approved manner to the inner face of the seat-frame of the chair, as shown in Fig. 1, and the inner end of the link 20 is preferably enlarged and provided upon its outer face with an integral projection 21, which projection maybe of polygonal contour, as illustrated in Fig. 1, or shaped to the form of a spur-wheel, as illustrated in Fig. 5.

\Vhen the construction shown in Fig. 1 is employed, the corresponding plate illustrated in Fig. 6 is also used, and when the construction set forth in Fig. 5 is used,which is the preferred constructiomthe plate shown in Fig. 7 is employed in connection with it.

In the center of the projection 21 of the link 20 a threaded aperture is formed,which extends entirely through the plate, and into this threaded aperture the inner end of the adjusting-screw 17 isentercd.

In operation, when the chair is to be used as a rocker, the adjusting-screw 18 is manipulated to throw the projection 21 out of its socket or recess in the plate 13, as illustrated in Fig. 2, and it will be observed that if the spring should break or become detached from IOC either the platform or the seat-frame of the chair the device will effectually prevent the upper portion of the chair from being carried violently backward and will sustain it in essentially its normal position. In the event that it is desired to lock the body of the chair to the platform, either in an upright or'in an inclined position, the adj Listing-screw 18 is manipulated to draw the projection 21 of the lever 20 into its recess or socket, as shown in Fig. 3, and when in this position a perfect and secure lock is obtained. It is evident that the adjusting-screw may be readily manipulated by the occupant of the chair, and that instead of the device being attached to one side only of the chair, as illustrated, it may be attached to both sides.

Having thus described my invention, 1- claim as new and desire to secure by Letters Patent- 1. In a safety attachment for platformrockers, the combination, with pivoted links, one of which is provided with a side projection formed near one end, having irregular edges, and a threaded aperture extending through the center of the projection and through the link, of a plate provided with a socket corresponding to the contour of the link projection and a set screw passed through the socket of the plate and into the threaded opening of the projection, substantially-as shown and described.

2. The combination, with the platform and the rocking seat-frame of a platform-rocker,

of two pivoted links, the upper end of the upper link being secured to the rocking seatframe and the inner end of the lower link provided with a projection upon its outer face, having irregular edges and acentral thread-opening, a plate secured. to the platform, provided with a socket corresponding in contour to the shape of thelink projection,

and an adjustin -screw passed through the said platform, the socket of the plate, and into the threaded hole of the link projection, substantially as shown and described,'and for the purpose specified.

The combination, with the platform and the rocking seat-frame of a platform-rocker, of pivoted links, the upper end of the upper link being adapted for attachment to the rocking seat-frame, and the inner end of the lower link provided with a projection upon its inner face, shaped substantially as a spurgear, and having a central threaded aperture, a plate attached to the platform, provided with a socket corresponding in contour to the shape of the link projection, and an-adjusting-screw passed through theplatform and the plate-socket into the threaded aperture of the link projection, substantially as and for the purpose specified.

RICHARD ll. KRALL.

Witnesses:

C. I). BoAs, JOHN L. SCHRUNK. 

